1. Field of the Invention
The present invention relates to modular building blocks and, in particular, to modular building blocks provided with interlocking reinforcement rods.
2. Description of the Related Art
It is known to provide modular building blocks with interlocking reinforcement rods. For example, U.S. Pat. No. 8,061,095 which issued on Nov. 22, 2011 to Bucheger discloses modular blocks provided with keys and keyways to allow for engagement of the blocks. The blocks are also provided with a vertical passageway through which reinforcement rods extend. Couplings are used to connect vertically aligned reinforcement rods. However, known modular building blocks with interlocking reinforcement rods are generally not provided with means to prevent rotation of the couplings. This may be problematic in cases where the couplings and reinforcement rods are threadedly connected. Rotation of couplings may result in the couplings and reinforcement rods coming unthreaded and the reinforcement capacity of the reinforcement rods being diminished.